Effects of Doping and C60 Coating on the Electrochemical Characteristics of Silicon Film Anodes for lithium Secondary Batteries

Abstract

Effects of B or P doping and Fullerene C60 film coating on the anodic characteristics of Si film are studied by electrochemical measurements such as charge-discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. Results show that the P doped Si (n-type) anodes coated by fullerene film coating exhibit a more enhanced cycle performance and smaller charge transfer resistance compared with those of intrinsic and B doped Si coated by fullerene film. The C60 coated n-type Si electrodes demonstrate a high discharge capacity above 3,000 mAhg-1 after 100th cycle under 0,3 C rate. The more enhanced electrochemical characteristics are attributed to the improvements of electronic conductivity of Si film by P doping and the suppression of side reactions with the electrolyte by the fullerene film coating.